1. Field of the Invention
The present invention relates to a pump; and more particularly relates to a diaphragm pump.
2. Brief Description of Related Art
Diaphragm pumps are known in the art, and take the form of positive displacement pumps that are configured with one or more chambers for pumping a fluid. Diaphragm pumps use check valves to allow fluids to pass in one direction either from an inlet side to an outlet side of a valve housing, or vice versa. In particular, a typical diaphragm pump uses a combination of the reciprocating action of a diaphragm and suitable non-return check valves to pump the fluid. The diaphragm is typically sealed with one side in the fluid to be pumped and flexed, causing the volume of the pump chamber to increase and decrease. A pair of non-return check valves prevent reverse flow of the fluid. In operation, when the volume of a chamber of the pump is increased (e.g., the diaphragm moving up), the pressure decreases, and fluid is drawn into the chamber. When the chamber pressure later increases from decreased volume (e.g., the diaphragm moving down), the fluid previously drawn in is forced out. Finally, the diaphragm moving up once again draws fluid into the chamber, completing the cycle.
FIG. 10 shows an example of one such umbrella style check valve used on rotary diaphragm pumps. The short comings of using such umbrella style check valves on rotary diaphragm pumps are that any particulates that gather under the valves will disrupt the priming and the pressure of the pumping process.